Coupler modification for steep grades

Model Railroader General Discussion (Model Railroader)
1

I’m having an issue with my longer engines (E8 or Alco PA) on the steep grade on my layout that leads to the second level. The transition from the grade to level isn’t perfect, and the length of these two engines in particular exacerbates the problem, meaning the rolling stock behind the engine often comes uncoupled, sending the rest of the train on a ghost ride down the tracks!

The layout is established and the grade works fine with the shorter engines, so I’m not going to tear out the grade and redo it (it’s also in a hard-to-reach area.) What I was thinking of doing was one of two things:

  1. Gluing on some sort of extension piece to the coupler to make it deeper so that when the rear end of the engine swings up, the coupler remains in contact with the coupler of the freight car behind it. It might not look great, but at this point, I’m more interested in not losing the train than I am prototype looks. If anyone has any suggestions on how to do this (or does someone make an extra deep coupler?), let me know.

  2. The other option would be to put some sort of small clamp on the couplers to keep them from separating. I was thinking a small paper clip put short-end down might hold them together, but not really sure.

If anyone has tried either of these options or has any other ideas, I’d like to hear them. It’s only two engines, so I’m not modifying the whole fleet for it, just looking for a quick fix when these two units are used to haul freight up the grade.

Thanks!

2

My answer, not what you want to hear, but, is…

This:

Fix the grade transition issue.

You will continue to have issues with it if you attempt any “band-aid” fix, like different couplers, or attempting to lock the couplers together.

You need to fix the issue, not the symptoms it creates.

Want a different answer? Ok, technically:

Kadee shelf style couplers, like 119’s, will not uncouple from each other without you trying very hard… And refuse to come apart by lifting. Just like the prototype shelf couplers, they are made to prevent “ride-up” of each other.

However, if the grade transition is bad enough to create an uncoupling issue, it will most likely derail anything with the 119’s on them… The railcars will lift off the rails when the engines hit the grade, thereby worsening our problems… Don’t ask me how I know this…

So, while not what you wanted to hear, my advice, still, is: Fix the grade transition issue, not the symptoms it creates.

Any other way will cause more issues.

EDIT:

[#welcome] to the forums.

If, changing the layout or fixing the grade is not optional, my next recommendation is to park the larger locomotives, ban them from entering the grade area, and stick with the smaller units that do not give issues.

Trying anything else will not help or work.

This comes from experience.

Either fix the grade, or park the larger locomotives that do not like it. Anything else will only frustrate you.

3

Ricky gave the two options. Fix the transitions to the grades or use shelf couplers - same as used on modern tank cars.

4

Listen to Ricky. Way back I acquired a whole bunch of cars that were equipped with Varney’s “dummy” knuckle couplers. Once those things were mated they stayed mated until you lifted one car up - and even then they’d often tenaciously cling together. In short they stayed coupled under all conditions just as you propose to try. Result? Even modest changes in track height that gave me no problems with other couplers caused problems with that block of cars (which I always ran together because the rest of my cars at the time were horn hooks).

When couplers are that tight, all the verticle forces that would otherwise cause a coupler to rise up and uncouple from the coupler behind it get translated to the car frame, trucks, wheels, and ultimately, the flanges. Those forces don’t go away just because you make changes to the couplers! So the flange is what rises rather than the coupler and when the flange rises far enough (the depth of a flange being far less than the height of a coupler knuckle) the car derails.

Is there a chance your coupler heights vary too much from NMRA standards? We get so used to accepting “just a little bit” above or below standards because as a rule the couplers still “work” ok, but when pushed to a limit as with your situation, Mr. Murphy sees to it that the lowest and highest couplers always seem to be mated with predictable results. I’d get pretty ruthless and militant about coupler heights and if the problem still exists, then yeah, it is time to address what sounds like a too abrupt (perhaps even angular) “verticle curve.” As track planner John Armstrong explained, you need transitions into verticle curves of a car length or two just as ideally you’d have transition easements into horizontal “radius” curves.

Dave Nelson

5

John Armstrong - head his wisdom on grade transitions.

6

I agree, shelf couplers will solve the problem! But beware once coupled you need an uncoupler to get them apart! I went to shelf couplers on all of my passenger cars and locomotives. It isn’t just imperfect track that cause long locomotives and long cars to uncouple.

I’ve never had a shelf coupler fail in years of use. I did have to install several unplanned uncouplers.

Mel

Modeling the early to mid 1950s SP in HO scale since 1951

My Model Railroad
http://melvineperry.blogspot.com/

Bakersfield

7

Check that all of your couplers perfectly match the Kadee height gauge. If some are low and some are high then they will uncouple on grade changes. Use under shank or over shank couplers to match the height, like Kadee #22 or #27.

As far as your grade, the problem is right at the start of the grade or at the top. You might need to fill in the transition some so it’s not so abrupt. Instead of going right into steep grade, instead go into half of it for a few inches and then another half to get your final grade. Same with down hill except you need to trim away some roadbed or sub-roadbed. You can still have steep grades, you just need to transistion into them.

8

Are you using Kadee couplers or clones?

9

How have you installed your track, if it is the modern caulk method, all you need to do is slide a puddy knife under the track for a short way and shim, hyad to fix one of mine that way.

10

Thanks for your reply. The trackage grade is not an easy fix because of its location and how it comes off a nearby turnout – plus it’s behind a large city section and would be difficult to work with. The grade has a transition, but apparently it’s not enough for the longer locos – especially the E unit.

I primarily use Kadees, and that’s all I use going forward, though there are still some clones in use on the layout. I’m pretty religious about coupler height, and anytime a car comes uncoupled, I stop and do an immediate inspection with the height gauge.

I don’t think there’s a huge problem with the grade, because the uncoupling doesn’t happen every time – I think it’s just barely slipping over on some couplers, which is why I thought if I could put on a “safety” device of some sort, it would eliminate the problem.

I’ll doublecheck my coupler heights and might give the shelf couplers a try, but if that doesn’t work, parking/banning the longer locos may be my only option. They are really a tad too big for my layout anyway, so maybe I could sell them and use the money to buy a few more shorter GPs or RS units that I like.

Thanks for all the suggestions.

11

PAs and E8s are passenger engines and should be pulling passenger cars. Between the engine and the first head-end car (baggage? R.P.O.?)revert back to horn-hooks and keep 'em together. They rarely come apart in use, but can be easily separated manually.

12

Indeed, they were passenger engines, but since passenger trains have been discontinued on my layout, they have been pressed into freight service, much like some (not all) of their real-world counterparts did.

13

Try Kadee 118’s on both sides, they will not come apart unless you want them to. They fit in place of a No. 5.

14

The issue is called “Hi-Lo” One is to high and the other is too low.

The correct solution is to fix the grade. It really is a simple matter to remove the tracks at the top of the grade, and with an electric sander lower the offending translation. At the bottom of the grade you can add shims to adjust the transition.

LION has replaced many tracks many times. And him even got 20 people together to lift and move the layout away from the wall. In the end you will be far more pleased with thisoot correct solution.

The other solution nobody has mentoned yet is to use drawbars between the ofening equipment. All trains of LION are joined by drawbars, not a coulper to be found on the layout. But then LION runs SUBWAY TRAINS with 48 wheel pickup, and these things laugh at curves, grades and crossings. Indeed, LION does not even bother to power the tracks through the interlocking plants.

ROAR

15

Fix the track is the best cure for this problem. If that is impossible, connect a 50 or 60 foot freight car to the locomotive with a drawbar and put a Kadee coupler on the end that connects to the train. This car would remain permanantly coupled to the loco. It’s shorter length should help the problem.

16

As a quick fix, I’ve used a short piece of shrink tubing of appropreate diameter over the couplers. A loose fit allows some vertical movement, but not enough to uncouple or pull the following car off the track. Down-side is, once coupled, it’s like a drawbar.

Paul O

17

Another solution would be to use a dummy coupler between the trailing unit and first car.

18

It kinda feels like some people are tuning out this part of the OP’s problem when reading the thread. Yes, a more gradual transition into the grade would probably be ideal from everything I’ve read, but this part turns making that adjustment from “simple quick fix” to “pain in the ETD that involves rebuilding half the layout”.

Longer locos can have similar issues when it comes to tight curves… I’m wondering if maybe converting the couplers on the offending pair to Talgo-style mounts in order to increase flexibility might help.

19

That is why some long passenger and freight cars can go around 18" curves. The overhang is totally gross but,around they go.